Golf practicing apparatus



9 Sheets-Sheet 1 Filed Jan. 28, 1949 Sum a an a l NVENTO R Geo/5 6M. Wazdmmfiaifg BY 9 Z ATTO RN EYS Jan. 20, 1953 JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 f 52 ix 1 57 61 .56

9 Sheets-Sheet 2 -1 I 49 ,4 22 I! ll 35 INVENTOR 2] 39 Gm/ge/HJMZ/Z/MWJZ IZZY,

ATTORNEYS.

Jan. 20, 1953 cs. M. T. JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 9 Sheets-Sheet 3 FIG: .1 50 55 Jan. 20, 1953 G. M. T. JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 9 Sheets-Sheet 4 INVENTOR. earggjyfi'owimizflims;

ATTHRNEI S.

Jan. 20, 1953 G. M. T. JENKS 2,626,151

GOLF PRACTICE APPARATUS yaw W ATTORNEYS.

Jan. 20, 1953 G. M. JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 9 Sheets-Sheet 6 J 'IGi Zl FIG 20.

BY fl? A TTORNE VS.

Jam 20, 1953 G. M. T. JENKS 2,626,151

GOLF PRACTICE APPARATUS I Filed Jan. 28, 1949 9 Sheets-Sheet v FIGEJI INVENTOR. fieargejlirowimamiz/fis,

YW W

ATTORNEYS.

Jan, 20, 1953 JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 9 Sheets-Sheet 8 I N V EN TOR:

r' ATTORNEYS. I130 Jan 26, 1953 3. M. T. JENKS 2,626,151

GOLF PRACTICE APPARATUS Filed Jan. 28, 1949 9 Sheets-Sheet 9 F I (i 35L INVENTQR; Hen/ 117. ZY'UZl/Zi/Zfb/Z Jen/v5,

A TTORNEYS.

Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE GOLF PRACTICING APPARATUS George M. Troutman J enks, St. Petersburg, Fla.

Application January 28, 1949, Serial No. 73,264

16 Claims. 1

This invention relates to a golf practice apparatus and more particularly concerns a golf practice apparatus adapted to coordinate the movement of different parts of a golfers body during the course of numerous practice swings for ultimate attainment of an ideal golf swing.

The broad idea of controlling the movement of a single member of a golfers body during the course of a practice swing has been for several years an accepted method of teaching and perfecting a golf swing. Among others, numerous devices have been proposed to date for restraining a golfers head to prevent him from looking up before the club head has contacted the ball. There are also devices on the market for preventing excessive sliding motion of the hips; while other devices have been devised to hold the right elbow in an elevated position during the swing of the club. Other harnesses and straps for restraining the shoulders have been marketed from time to time, but the foregoing devices do not appear to have met with any great success because they correct the motion of only one part of the body while permitting other parts of the body to repeat old mistakes or even to develop new incorrect motions as a result of the restriction of the corrected member. In order to teach an ideal golf swing by restricting the movements of a golfers body, I have found that it is necessary to treat the entire body as a unit and coordinate the individual motions of the several pertinent parts of a golfers body in such a way that the movement of any single part of the body is dependent upon the movements of other parts. To my knowledge the various devices of the prior art have failed to do this and have consequently failed to accomplish their broad purpose.

It is accordingly an object of this invention to provide a golf practice device which coordinates the individual motions of the principal parts of a golfers body and thereby teaches an ideal golf swing.

A further object is to provide a mechanism for correlating the motions of the golfers hands, wrists, arms, head, shoulders, hips, knees, and feet into one integrated motion.

A still further object of this invention is to provide a golf practice apparatus for holding various parts of a golfers body in definitely spaced relationship during successive stages of the golf swing.

A further object is to provide a means for controlling the respective motions of difierent parts of a golfers body so that the motion of a single body member is actuated by movements of other parts of the body. Another object of this invention is to provide a mechanism adapted to be attached to the body of the golfer that receives an initial force from the hands, arms and shoulders of the golfer and transmits said force to other parts of the golfers body to create an integrated coordinated motion through the entire course of a golf swing.

Other objects and means for attaining them will appear from the accompanying drawings wherein:

Fig. 1 is a view in side elevation of a golf practice apparatus conveniently embodying the present improvements, with portions thereof broken out to expose important details which would otherwise be hidden, and showing a practice golfer in the act of executing a golf swing.

Fig. 2 is a fragmentary view in longitudinal section of a portion of the mechanism for controlling the arm and wrist movements of the practice golfer.

Fig. 3 is a fragmentary view in top plan looking as indicated by the angled arrows III-III in Fig. 2.

Fig. 4 is a fragmentary view in section taken as indicated by the angled arrows IV-IV in Fig. 2.

Fig. 5 is a View partly in elevation and partly in vertical section taken as indicated by the angled arrows V-V in Figs. 2 and 1.

Fig. 6 is a View in longitudinal section of another portion of the arm'and wrist motion control mechanism.

Fig. '7 is a fragmentary view in top plan looking as indicated by the angled arrows VII-VII in Fig. 1.

Fig. 8 is a view in side elevation looking toward the bottom of Fig. '7.

Figs. '9 and 10 are horizontal sectional views taken as indicated respectively by the angled arrows IX-IX and XX in Fig. 1.

Fig. 11 is a fragmentary view in top plan showing foot plates on which the practiced golfer is adapted to stand, and the parts by which said plates are directly actuated during the execution of a golf swing.

Fig. 12 is a fragmentary view in vertical section taken as indicated by the angled arrows XIIXII in Fig. 11.

Fig. 13 is a fragmentary view in longitudinal section of the means provided for controlling the head movements of the golfer incident to swinging the golf club; and

v Fig. 14 is a horizontal sectional view taken as ducing record graphs or generating templates for use in cutting different cams instrumental. in.

bringing about the desired arm, hand hip and foot movements necessary toanideal golf 'swing'.

Fig. 22 is a perspective view of a portion of.

the linkage illustrated in Figs. 2 and 3.

I have discovered from studying the gol'fswifigs of leading golfers bothduring actual play and from photographs, that although thererare individual differences of minor: nature in their strokes, there is a substantial similarity'in the basic patterns of motion. of the diffe'rentpa'rts of the body and a definite relationship of the timing of these motions withrespect to each other; A detailed analysisof the'armmotions discloses th'atthe arms traveluin substantially: a single plane in the swingrofmo'st' experts and that the handsdescribe a nearlyv circular. are about a centerin-the neighborhood of the :left shoulder. During the swing of the arms, the wrists are cocked and uncooked indefinite relationship. with the rest of the golf swing. The hips movein' a definite relationship to 'the'movements of the hands and wrists and describe a combined rotary and sliding "motion. Similarly the feet and knees movein-relation with the other members of the body.

With more detailed reference first more particularly to Figs; 1 and'9' of these illustrations, it will be seen that my improved golf practice apparatus comprises a base I whichserves as a platform and which has divergently arranged inset foot plates 2 and 3 adjacent one end thereof.whereon the golf player is adapted to stand. Rising from the base I at the opposite end to the front of the players' station is a-hollow'post i witha telescopic extension-.5 which is vertically adjustable and securable in "adjusted positions by a hand screw-6; Supported by'the'post is a mechanism 1 by which the arm, hand and wrist movements essential to the executionof an ideal swing of a golf club C grasped in :the hands of the player, are controlled. The mechanism '1 includes an L-sliaped bracket B'wh'ich is pivotally adjustable about the axis of a manually operable clamp screw 9" at the top ofp'ost t, the upstanding portion of said bracketbeing hollow and terminating in spherical h-e'ad- H) (see Fig. 2). In preparation for the use of the apparatus, thead justmentsat 1 and "8*are'so made that the axis of an inclinedshaftl l'journalled in the head [0, wouldif extended,- pass approximately through the left shoulder? of the playerv standing on the platform: I. Slidably' mounted on a tubular radial projection [2 of the head H} through which the shaft .l I passes, is a cylindrichousing I3 whereof the. central hub l4 fits slidingly over said projection: The shaft II is not only rotatable in the head 19, but axially shiftable as well against th force of a compression spring I5 for a purpose later explained. Through engagement of a fixed collar l6 onthe shaft II with the outer. end. of

4 the hub IA of the housing IS, the housing l3 together with the parts contained therein and the elements yet to be described connected to them are caused to move axially with said shaft. Anchored in a lug I? at the top of head I0 is a pin H3 with which an eccentrically disposed boss I9 at the back of housing [3 is slidingly engaged to prevent rotation of the latter as it is axially shifted. To the front end of shaft II is afiixed a fork 20 whereof the extremities M are pivoted at 2'! to the extremities of an oppositely arranged fork 22 at the contiguous end of a tubular shaft 23 extending at an obtuse angle to said shaft ll toward the players station. Secured to shaft 23, at its distal end, is a hollow a-rm---2'4: Rotatable in an angularly disposed bearingyZS; which is fixed to the outer end of arm 24, is a sleeve 25, see Fig. 6, through which thGhand-le end of the golf club C is passed and in which said club isremovably secured by a clutch collar indicated at 21. Axially within the tubularishaft 23 is an independently rotative shaft: 28 composed of telescoping sections from which motion is transmitted, through a pair of bevel gears 2Q; 39, to a shaft 3! withinthe hollow arm 26; and from the latter shaft through another pair of bevel gears 32, 33, to the sleeve'26 in which the golfclub C is held to induce the desired wrist movements of the practice golfer. The shaft 28 (Figs. 2 and 3) protrudes from the upperend of tube 23 where, through a universal joint. 34 it is coupled with a short shaft '35 which is rotative in a bearing 35 on a carriage 31 disposed within the frontal upper part of the housing l3. As shown, the carriage 31 has outward arms 38 pivoted at the top which, through similarly pivoted links 39, are pivotally coupled with arms 40 upstanding from the extremities ii of the fork ill. The carriage 37 also has pendent arms'42 pivotally connected to arms 43 independently of shaft H and hub is andextending from the yoke- 22 beyond the pivots 2|. The pivotally connected arms 39, d0, 42, 43 constitute a pair of spaced-apart, collapsible parallelogram-linkages. Afiixed to the inner end'of shaft 35 is-a spur pinion 45 that meshes with aspurgear '46 on a parallel shaft 4? rotatab ly ,a circumferential groove inthe hub of the gear 46-whereby said gear will be shifted longitudinally on the shaft M as said arm 56 moves about its pivot 55. The means for shifting the roller arm 55 comprises a push-pull solenoid 6| whereof the armature 52 bears against one side of said arm. The spring shown at '63 serves to normally maintain theIGllBI 58 in the position in which itis shown in Fig. 2, while springs 64 in tension between the arms ii] of forkffl and a collar 6 30. free on shaft 28, urge collar 64a against the upper end of tube 23 and accordingly urge the carriage 3i upwardly within thezhousing l3, and rollerffl against cams 58, 59.

Afhxed to the end of shaft 1 l protruding from the :back of the head It is an arm 55 whereto is pivotally connected a smaller arm 66 with a roller 61 thereon arranged to be shifted at different times during the execution of a golf swing, as later on explained, from one to the other of two concentric cam rings 68, 69 rigidly secured to said head I 0. For the purpose of shifting the roller 61 between these cams 68, 69 ther is provided a pull solenoid 16 on arm 65 whereof the armature II is coupled with lever projection 12 on the arm 66. Cam rings 68, 59 have specifically shaped surfaces contacting roller 61, serving to move roller 61 bodily toward and away from the lug I 1, thus causing controlled axial movement of shaft II, during the course of the golf swing.

The foot plates 2 and 3 (Figs. 1, 9 and 11) are disposed within openings in the top of platform I, and connected to said platform by hinges 80 for capacity to rock independently up and down within said openings. The means for actuating the foot plates 2 and 3 includes a pair of rotary cams 8! and 82 afiixed side by side on a horizontal shaft 83 beneath the platform I. As shown in Figs. 11 and 12 the cams 8| and 82 are engaged by rollers 84, 85 on bell cranks 86, 81 which are rockably supported by fixed bearings and connected by links 88 and 89 to the respective foot plates 2 and 3. The spring indicated at 86a acts upon the bell cranks 66, 81 to keep the rollers 84, 85 in engagement with cams 3 I, 82.

The means relied upon to induce the desired back hip, and knee movements during the club swing includes a belt 96 which is attached about the waist of the player. At opposite sides and at the back, the belt 90 has pivotal connections with the upper ends of upright link rods 9I, 92 and 93. As shown in Fig. 9, the rods 9|, 92 extend down through arcuate clearance slots 95 in the top of platform I, and at their lower ends are connected to the tops of upright arms 96, 91, medially pivoted on the outer ends of horizontal arms I00, IIlI, fulcrumed for independent up and down movement, to a fixed collar I02 on a vertical shaft I63 which extends down through the platform I in the axis center of the arcuate slots 95. Rollers I85, I66 at the outer ends of arms I00, IOI run on the bottom edge of an arcuate cam I01 affixed to platform I in concentric relation to shaft I63, while rollers I68, I89 at the lower ends of the arms 05, run against the outer circumferential face of an arcuate cam H0. The bottom end of rod 93 is similarly connected to the upper end of a vertical arm I I I which is rockably supported at the end of a third radial arm II2 capable of up and down movement about a pivotal connection with a collar II3, on vertical shaft I63 above the platform I. Likewise as shown, the arm III is provided with a roller II4 to run against the outer circumferential face of an arcuate cam II5 on the platform I, and the radial arm I I2 with a roller II6 to run on the top edge of arcuate cam II 1 above platform I. Springs H8, H9 and I25], influential upon the arms 96 and II I, serve to hold the rollers I05, I86 and H4 to the cams I 61 and H5, respectively.

Rotary motion is imparted to vertical shaft I63, through gears I20a, IZI, from the horizontal shaft 83 which is arranged to be actuated in turn through bevel gears I22, I23 by a Vickers hydraulic transmission unit I25 (Figs. 1, 7 and 8), located together with an electric motor I26, beneath the platform I. Associated with the motor I26 is a speed reducer I21 to one end of the output shaft I28 of which is secured a cam disk I29. This cam disk I29 is engaged by a roller I30 on a rocker arm I 3I connected by a link rod I32 to the lever I33 of the control I35 on the transmission unit I 25. Alongside the unit I25 and operatively connected thereto by a belt I36, is a second hydraulic transmission unit I31 with a control I38 whereof the actuating arm I39 is coupled, through a link rod I40, with a rocker arm I4I having a roller I42 bearing upon the periphery of a rotary cam I43 at the other end of the shaft I28 of speed reducer I21. By means of bevel gears I45, I46 the unit I31 is connected to one end of another horizontal shaft I41, the distal end of which is in turn connected by bevel gears, I48, I49 (Fig. 1) to a short vertical shaft I50 rotatively supported in a suitable bearing on top of platform immediately forward of the post 4. Through a universal joint I5I, shaft I56 is connected to the lower end of extensible link I52 whereof the component sections are telescopically interengaged, and whereof the upper section I53 is connected by universal joint I55 to the bottom end of a shaft I55a (Fig. 2) rotatably supported in the hollow upright portion of angular bracket 8. A bevel gear I56, (Fig. 2) at the top end of shaft I55a meshes with a bevel gear I51 splined to shaft II within the spherical head I0. As a consequence of the interposed connections just described, it will be seen that the back, hip, knee and ankle movements of the golfer are all controlled by the mechanism of Fig. '1 in properly timed relation with the arm and hand movements during the execution of a golf swing.

The means provided for controlling the head movements of the practice golfer as he swings the club C, includes a cap I60, see Figs. 1, l3 and 14. This cap I60 is secured by a jaw strap I6I, and extending over the top thereof from opposite sides of a crown band I62 is an arch piece I 63 with a central upstandin stud I65. As shown, the stud I65 has an enlargement I66 at its upward end which fits, with capacity for rotation, into a fixed spherical socket member I61 at the end of a tubular support I68. Independently pivoted on the enlargement I66 of stud I 65 are arcuate shoes I69 which are normally maintained in frictional engagement with the inner surface of the socket I61 by springs I10 to prevent rotation of the cap I60 and hence of the golfers head until after the ball is contacted by the club C as later on explained, and which are arranged to be withdrawn upon energization of an electrical magnet I1I fixed upon said enlargement. The support I68 is in the form of a diametrically reduced flexible prolongation of the upper vertically adjustable section I12 of a tubular post I13 immediately to the rear of the golfers station on the platform I. The prolongation I12 is fixable if; usted positions by the clamp screw indicated a As diagrammatically shown in Fig. 15, current flow to the coils of the roller arm shifting solenoids 6| and 10 is controlled by a switch I16, which, see Figs. 2 and 4, is mounted on the back of head I 0 with its actuating lever I11 in the path of a stud I18 extending outward through an arcuate slot I19 from a disk I within said head. The disk I80 is free on a spacing sleeve I8I surrounding the shaft II within the head .I0 and frictionally engaged by the flanged end of a slide sleeve I82 which fits over the hub of bevel gear I51. The sleeve I82 is subject to the action of a compression spring I83 and obliged to rotate with gear I51 through engagement of diametral slots therein with pin projections I85 on the gear hub. This arrangement is such that the stud I13 is moved away from the switch lever I11 during a'eaeyisi.

'tlie driv'e'swing of th golf club, and moved with" six teeth adapted to be picked-one ata" time I by a pawl I95. Freely" oscillatable about the shaft I9I is a spring pulled'arm I96 which'carriesthe pawl I95, and which, through a rod I91, is'coupled'to theiarm'ature I98 of a .pullsolenoid I99'in'terposed in'a current supplylineszflfl, 28L Current flow through the coil of. solenoid' I.99.is controlled by "a rotary switch. 252 which, see. Figs. 1 and 17, is supported by anupwardly reaching arm 293on bracket 8 (Fig. 1) that carries the mechanism 1. The diametrically reduced rear end of shaft I I extends axiallythrough' the'casing 294'of switch 292, and splinedto it is. a disk 255 which is confined to'rotation in. said casing, see Fig. 17'. Projecting from the disk 295 is'ian eccentrically disposed stud 295 whichis yieldingly engaged by the radial arm 291a of acoiled contact spring 297 afiixedto an axial bearing boss 298 of casing 294; The contact stud at .259 projects from a'holderpiece 2 I 9 of insulation secured to the switch casing 294 with capacityforadjustment circumferentially thereabout, and-extends into the path of the radial arm of contact spring 251. The terminals of'current supplylin'e 299, 291 in which the solenoid coil I99 is interposed are'connected respectively tothe shaft I I and the contact 299. By closing of a push button switch ZIIin a branch circuit 2I2, 2I3it-is possible to operate the solenoid I99 forapurpose: also later explained. Likewise, the'ratchet' wheel I99 and the parts associated therewithmay 'beplacedin any convenient location, for example,- an arm :2-93 (Fig.1) which'supports'the switch 292. The-wiring'from the switch 292 to the magnet-I'll for holding, the cap against rotation is in -p'ractice run beneath the platform I andth-reade'd up through" the. hollow post .I I3 and its' hollow prolongations H2 and I68.

Operation Let it be assumed that the player'h'as taken his position on the platform with his feet engaged in the straps 2a and 3a of the foot plates '2 and 3, that-the posts Iand I13 have been adjusted to set the mechanism 7 and'the cap'ISU'atth'e proper height, that the cap has been strapped'to his head, and that the belt Sa'l'has been secured about his waist, all as shown in Fig.1. With his -head-now facing forwardly, the player or an attendant then pushes the button 2II with the result that the solenoid I99 is energized and the ratchet wheel I93 racked by one tooth to move thearm' I92 on shaft I9I to the broken lineposishaftz28- inside tubular shaft 23. transmitted to the shaft 28 from shaft 35' (Fig. 2')

stantiallyin the line of shaft "I I .his handsbeing incidentally raised and lowered by. swinging movement of-the tubular shaft: 23 about itspivotal connectionatfi I in response to the action of cams- 53-;-59-(which move-roller 51 towardand away: from' shaft I I driving-the swing) with corresponding change in the relationship" of: the parts constitutingthe parallelogram 3I, 39, 40 and 3'3"b5l1Whl-Ch the'shaft 23 and the *clubholder are-sustained from the-mechanism I. The movement-ofthe: golfers handsrelative to his-own body is governed through concurrent axial shifting;of shaft" I'Ibyaction of-cam 68,59 upon roller't'l. Thegolfershands' arethus adjusted in: position toward and'awayirom his body duringfithe. course of-the' swing. Also at the same time; a twisting movement is concurrently imparted to the players wristsby rotation of the This motion is byvth-e:gears-45,48-as-the roller 59 travels in the groove-of cam 51, and from said shaft 28 to the club holder sleeve "2? (Fig. 6) through the shaft 3I' and bevel gears 29, 35-, 32 and 33. At the moment-of contact of the club with the ball; the various parts of'the control mechanism occupy the positions in which they'are' shown in Figs; 3 and 5.

At about the'time that theball is-struck with theclub C, the'spring contact 291a (Fig. 16) encounters the fixed contact 299 to'close the circuit 299; 2I3I through'th'e solenoid I99:which is thereby energized and-the ratchet wheel I94 racked another tooth .to move the arm I92a into. engagement with fixed contact I93. The-circuit II'I, I18 is accordingly closed and themagnet III energ-ized to'with'draw the brakeshoes- I59 -so that the playerm-ay nowmove his head to follow the flight-of the-ball as he completes the drive swing. Upon initiation of the reverse or back swing, the'stud- I'I8 (Figs. 2 and 4) 'moves into engagement with the arm II'I of switch I16 to close the circuit (Fig. 15) through the solenoids GI and 19 which will thereby be energized to cause shifting of the rollers 59 and 5I'from the cams 5I' and 58- to thecams-52 and 59:as shown in broken lines in Fig. 2, and shiftingof-the roller 57 at the same time from cam :83 to cam 59. Thus during the back-swing, the-roller 51-wi11 be acted upon by the cam- 59, the roller 53 by cam 52, and the'roller 51 by cam I59. Accordingly, the movements then imparted to the arms, hands and wrists of the golfer willabe different from those'impar-ted during the drive swing as prescribed by the different shaping-of cams 52, 59 and 59. As theshaft II (Fig. 2) turns as above explained, motion is transmitted by the gears I53, I5? to vertical shaft l55-and from the-latter, through bevel gears I43, I49- (Fig; 1) to shaft I41,- which through bevel gears I andlt, is'coupled with transmission unit.I3'I (Fig.7) driven together with. transmissiomunit. I25-.by-electric motor I26. The cams I29 and I53 ontheshaft of speed reducer I37 associatedwith motor I26 so govern the operation of the-units I3? and I25 that the shaft 33, connected to the latter unit by the'bevel gears 12-2 and I23, is turned at the proper speeds and in the'proper directions for communication to the vertical shaft I93, through bevel gearsIZIl, IZI, of the required motions for actuation of 'the means by which the players' hip, back and ankle movements are forced. Thus in practice with my improved apparatus; all of the body movements of the golferarecoordinated-in timed relation, so :that by persistence; he will ultimately acquire an ideal swing. By employing the relay power devices I25, I26, I31 in the way described, no restraint is imposed upon the player to interfere with the ready and easy swing of the club.

In initially setting up the apparatus, it is theoretically possible to make geometric calculations based upon detailed analysis of photographs of an expert golfers swing and so arrive at adequate curves for the various cams embodied in the interconnected mechanisms of the apparatus. However, the results obtained by this method are at best only approximate, and I accordingly prefer to determine the shape of the several cams experimentally by having a golf expert, preferably one noted as a golf stylist, swing the club C in the apparatus. To prepare the apparatus for this purpose, the solenoid BI is removed from the link 39, and the arm 66 with its roller t! removed from the arm 65 at the rear end of shaft H. After removal of these parts, a relatively stiff disk 22!! (Fig. 18) with a paper chart facing 22f is placed, with interposition of a resilient cushioning gasket 222, into the back of housing 13. An annular retaining element 223 is thereupon inserted into the housing 53 and temporarily secured by screws 224, and another chart sheet 225 applied to the recessed frontal face of said element. Another annular retaining element 226 is next temporarily secured by screws 221 to the back of the head it and a chart band 228 applied to the interior thereof. For marking the chart sheet 221, a stylus 233 with a backing spring 23! is inserted into the axial bore of the stud 49 by which the roller is ordinarily supported on gear 46. For marking the chart sheet 225, a second stylus 232 with a backing spring 233 is provided, the same being inserted into the socket of a holder 234 temporarily secured to the carriage 37, so that the axis thereof corresponds in position to the axis of the roller 5'! which it replaces. For marking the chart band 228, a third spring pressed stylus 235 is used in a projection 23S detachably secured temporarily to arm 65 by a screw 231, the point of said stylus being positioned to correspond with the tangent point of the roller 6? which it replaces. With this preparation, an expert player is called upon to execute several swings during each of which the stylii 230, 232, and 235 trace several different curves on the respective charts 22!, 225, and 228 respectively during drive and back swings of the club. A geometrically mean path is taken in each instance which will give the optimum shape for the corresponding cam necessary to the execution of an ideal swing by the practice player. The mean curves thus obtained may be kept for record purposes or used as guides or templates in cutting the cams.

Graphs of the hip and foot movements of a golf player are obtained in a generally similar way as shown in Figs. 19, 20 and 21, by the fol-.- lcwing proced re: The segmental cams fill, H6, 2 l5 i I! l) are removed and respectively replaced by segmental supports 24s, 24:, 242 and 243, for marking sheets 244, 245, 245 and 24?. The cam rollers Hi5, 88, H4 and H5 are also removed and replaced respectively by stylii 248, 249, 255i and 25! to mark the respective sheets. The rotary cams 3i and 82, (Figs. 11 and 12) are in turn removed from the shaft 83 and replaced by plain disks 252, 2253 (Figs. 20 and 21) for the support of marking sheets 254, 255, and the rollers 84 and 85 replaced by stylii 253 and 251 respectively. With the apparatus as now prepared, the golf player executes a free club swing incident to which the attendant hip and foot movements are transmitted through the rods 92, 93 and foot plates and intermediate parts to the several arms 96, "II, III, H2, and recorded by the stylii 248-25I and 256, 25! upon the marking sheets or charts 244-241 and 254, 255 in a manner which will be readily understood.

An advantage attained in the use of the particular mechanisms described herein is that the cams that control the exact courses of movement are removable and replaceable. This means that the golf swing to be taught to a small person need not be the same as the one studied by a tall player, since changes of the cams can be made in a reasonably short time. The replaceability feature has the additional advantage that the swings of expert golf players having widely varied physical statures can be permanently recorded and reproduced.

The remarkable adaptability of the machine is further demonstrated by the ease with which it can be connected to accommodate a lefthanded golfer. An appropriate left-handed golf club is inserted in the holder clamp 21 and the various cams of desired shape are inserted in their respective places and the golf practice device is ready for use. Moreover, reverse cams may be made using curves developed by right handed experts thereby affording an opportunity for left-handed golfers to achieve the usual accuracy attributed to several right-handed golf experts.

Upon reflection it will be apparent that the apparatus I have shown in the drawings and described in the specification herein is only a highly perfected embodiment of my basic invention and numerous other mechanical means for coordinating the motion of respective parts of a golfers body during his swing will readily occur to persons familiar with the mechanical arts upon reading this disclosure. Accordingly I do not limit my claims to the precise details of the mechanisms illustrated in the drawings but intend them to cover my invention in its entirety.

Having thus described my invention, I claim:

1. A speed-synchronized golf practice device comprising a club holder, a support therefor, connecting means between said holder and support for controlling the movement of the hands and arms of a golf player, motion restrictive mechanism responsive to the motion of the golf players swing and adapted to control the movement of a remote, participating portion of the golf players body in three dimensions in interdependent relation with the motion of said swing, an external source of rotary power, a pair of hydraulic speed changers both connected to and driven by said source of rotary power, a pair of cams driven by said power source, means controlled by the surface shape of one of said cams for controlling the output speed of one of said hydraulic speed changers, connecting means for transmitting the driving force of said hydraulic speed changer to the mechanism for controlling the motion of the golf players hands and arms, means controlled by the surface shape of the other of said cams for controlling the output speed of the other of said hydraulic speed changers, and connecting means for transmitting the driving force of said other hydraulic speed changer to the mechanism for controlling the motion of said other portion of the golf players body.

2. Golf practice apparatus comprising a plat- 1 1i form with a station at one end fora practice golfer, mechanism sup-ported by r the platform with a ,shaft extending therefrom toward, .the' golfers 'station having a support at its distal end for a golf club to-be swung by the=golfer, a poston the platform to the rear of the golfers station ,rotatably supporting a-cap adapted to be non-rotatablyaffixedto the head of the golfer, brake-means for normally restraining rotation of the cap'to prevent the golfer from turning his head, and control means controlledfrom the mechanism and effective upon .saidbrake means to release the-restraining means in predeter' mined relation to the operation of said mechanismata definite time during the golf swing.

3. Agolf practice apparatus for coordinating the motions of'the hands and-arms of a golf playerand forcing them to execute a-pre-selected swing of a golf club, -whicncomprises a club holder, a support therefor, and a restrictive mechanism connecting said club holder and support and adapted to=control the path of said golf club in'three dimensions in its swing, another restrictive mechanism including a cam mounted on said support, a cam'follower in contact =With saidcam, and'a golf club turningidevice attached to'said cam follower and actuate'd by said cam, said turning device'being'driven by the force of said swing ininterdepen'dent relation to theaotionof the first mentioned restrictive mechanism and including an eccentric cam follower constructed and arranged to turn-the golf club about'the axisof itsshaftat varying rates of ,speed in' predetermined relation to the position of the golf club 'intheswing.

4. A-golf practice apparatus for coordinating the motions of the hands and arms of a golf player and-forcing them to execute the combined motions of a pie-selected golf swing, comprising a golf club holder, a support therefor, and a restrictive mechanism connecting said club holder and support comprising a first cam supported on saidsupport and a first cam follower attached to said club holder and in contact with said first cam to control the motion of the players-ar-rns from sideto side, a second cam alsosupported on said support and operative in a plane substantially at right angles to said first cam, a second cam follower attached to said club holder and-in contact with said second cam to-control the motion of the players arms forwardly and rearwardl-y' toward and away from the front of the playersbodyin dependent relation to the movement of the arms from side to side, golf club turning means; a third cam,- a follower eccentrically mounted in contact with-said third cam and attached to said golf club turning means to turn the golf club'around its axis at varying rates of speed in predeterminedrelation to the positions of the cam followers in the swing.

5. A'golf practice apparatus for coordinating the motions of the hands and arms of agolf player and forcing themtoexecute the combined motions-of a-pre-selecte'd golf swing, comprising a support, golf club holding -means, a 'tube connected to said holding means,'=a first cam'follower attached to said tube, a first cam supported by said support and contacting said cam first follower, said first cam having an irregularly shaped I cam surface constructed and arranged to regulate the motion .of the golf players armsifrom side to side, a second cam follower attached .to said tube, a second cam supported by saidgsupport and contacting said-.-second :cam follower,

said second cam having: an'irregularly shaped cam. surface constructed and arranged to regulate the motion of the golf playersarms inwardly and outwardly toward andaway from the front of the players'body, athirdcammountedon said support, a third camfollower in contact with-said third cam, a drive shaft disposed in said hollow tube'and connected to said third cam follower and to said golf club, the drive shaft being constructed and arranged toreceive and transmit impulses from the cam follower to turn the club about its axis at different rotation rates during the swing of the club in definite relation to the aforementioned movements of the golfers arms.

6. Apparatus as defined in claim 5 wherein one cam surface consists of two interconnected parts respectively controlling the movement of the club during the backswing and the downswing, and switching means are positioned on said support to switch the corresponding cam follower from one part of said cam surface to the other, said switching means being actuated at predetermined-points by the swing of the club.

7. A speed-synchronized golf practice device comprising a club holder, a support therefor, mechanism disposed'between said holder and support for controlling the movement of the hands and arms of a golf player, a second mechanism adapted to control the movement of a remote, participating portion of the golf player s body in three dimensions, a pair of variable speed actuators each connected to one of said mechanisms, an external prime mover drivingly connected to both'of said-variable speed actuators, and differentiallyvariable speed control apparatus on said variable speed actuators, and cam means movable in response to the revolution of said prime mover and effectiveupon said speed control apparatus to vary the relative speeds of said variable speed actuators at pre-selected points during each swing of the'club.

8. Apparatus as defined in claim 7 wherein the interconnected interdependent means for controlling and varying the relative speeds of said speed varying devices are also adapted to change the relative directions of movement of said speed varying devices.

9. Golf practice apparatus comprising a club holder, a support therefor and restrictive means including a shaft connecting said club holder to said support, said restrictive means also including a first control means fixed on said support and operative as-the club is swung by the golfer to determine movement of his armsthrough a prescribed arc, second-control means also fixed on said support in fixed position relative to said first control means, and thereby interconnected with and dependent upon said first meansand adapted to determine concurrent endwise movement of the shaft to determine cocked movements of the golfers Wrists, and third control means also fixed on said support in fixed position relative to said first and second control means and thereby interconnected with and dependent upon said first and second means, said third means, incl d ng a cam and a cam foll we .7 5 tatable at varying speeds about its axis under the influence of said cam, and thereby being constructed and arranged to determine turning movement of the club about its axis in the holder for impartation of prescribed twist movements to the wrists in predetermined relationship to the movements of the hands and arms.

10. Golf practice apparatus comprising a club holder, a support therefor, and restrictive mechanism connecting said support and club holder, said restrictive mechanism including a fixed shaft having a fixed axis but slidably and rotatably mounted on said support, a cam surrounding said fixed shaft and a cam follower afi'ixed to said shaft and held in contact with said cam to shift the shaft axially under the influence of the cam, a second cam surrounding said fixed shaft in definite fixed position relative to the first cam, a second shaft pivotally attached to and supported from the fixed shaft, and also attached to said club holder, and a cam follower attached to said second shaft and held in contact with the second cam to control the angle of inclination of the second shaft relative to the fixed shaft in definite relation to the axial shift of said fixed shaft during the swing of the club holder.

11. Golf practice apparatus for controlling the arc of a golf players swing comprising a club holder, a support therefor, first control means supported by said support, connecting means responsive to said control means and attached to said club holder to move it in a controlled path toward and away from the center of said arc, second control means mounted on said support in definite predetermined fixed position relative to said first control means and also effective upon said connecting means to move said club holder toward and away from the golfers body in predetermined relation to its movement toward and away from the center of the arc during the course of said swing.

12. Golf practice apparatus comprising a support, a rock shaft axially slidable on said support, first cam means for sliding said rock shaft axially in response to its rocking movement, a club holder arm pivotally supported on a pivot transverse to the axis of said rock shaft, second cam means for swinging said club holder arm about said pivot also in response to the rocking movement of said rock shaft, and in definite predetermined relation to said axial movement, and means for attaching a golf club to said club holder arm.

13. Golf practice apparatus comprising a support, a rock shaft axially slidable on said support, first cam means for sliding said rock shaft axially in response to its rocking movement, a hollow club holder arm pivotally supported on a pivot transverse to the axis of said rock shaft, second cam means for swinging said club holder arm about said pivot also in response to the rocking movement of said rock shaft, an independently rotative shaft disposed within said hollow shaft, third cam means for rotating said independently rotative shaft also in response to the rocking movement of said rock shaft, means for attaching a golf club to said club holder arm, and connecting means for transmitting the rotary movement of said independently rotative shaft to rotate said golf club about its axis.

14. Golf practice apparatus comprising a support, a rock shaft axially slidable on said support, first cam means for sliding said rock shaft axially in response to its rocking movement, a club holder arm pivotally supported on a pivot transverse to the axis of said rock shaft, second cam means for swinging said club holder arm about said pivot also in response to the rocking movement of said rock shaft, and in definite predetermined relation to said axial movement, means for attaching a golf club to said club holder arm, restrictive means for attachment to a remote portion of the golf players body, remote cam means and follower means effective upon said restrictive means, and connect- 14 ing shaft means coupled to said rock shaft and to said remote cam means to control the movement of said remote part of the golfers body in three dimensions in response to the rocking movement of said rock shaft.

15. Golf practice apparatus comprising a support, a rock shaft axially slidable on said support, first cam means for sliding said rock shaft axially in response to its rocking movement, a club holder arm pivotally supported on a pivot supported by the rock shaft transverse to the axis of said rock shaft, second cam means for swinging said club holder arm about said pivot also in response to the rocking movement of said rock shaft, and in definite predetermined relation to said axial movement, means for attaching a golf club to said club holder arm, harness means for attachment in fixed position to the golfers head, brake means including a first element attached to said harness means and a brake element effective upon said first element to lock said harness in fixed position, magnetic means for moving said brake element relative to said first element, and switch means mounted in predetermined position relative to said rock shaft and connected to said magnetic means, whereby the harness means is locked and released in predetermined relation to the movement of said rock shaft.

16. A golf practice apparatus comprising a club holder, a support therefor, connecting means including a cam and follower between said holder and support for controlling in three dimensions the movements of the hands and arms of a golf player, a hip controlling device connected to said connecting means and responsive to the motion of the connecting means, and adapted to control the movement of the golf players hips in three dimensions in interdependent relation with the movements of the golf players hands and arms, a constant speed source of rotary power, a pair of hydraulic speed changers both connected to and driven at substantially equal speeds by said source of rotary power, a pair of cams driven at substantially equal speeds by said power source, means responsive to the surface shape of one of said cams for controlling the output speed of one of said hydraulic speed changers, connecting means for transmitting the driving force of said hydraulic speed changer to the mechanism for controlling the motion of the golfers hips and feet, means responsive to the surface shape of the other of said cams for controlling the output speed of the other of said hydraulic speed changers, and connecting means for transmitting the driving force of said other hydraulic speed changer to the mechanism for controlling the motion of the golf players hands and wrists.

GEORGE M. TROUTMAN JENKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,604,118 Glancey Oct. 26, 1926 1,936,143 Shea Nov. 21, 1933 2,179,663 Link Nov. 14, 1939 2,189,613 Paulsen Feb. 6, 1940 2,299,781 Adams Oct. 27, 1942 2,328,408 Bell et al. Aug. 31, 1943 2,458,932 Cottingham Jan. 11, 1949 2,468,033 Byers et al. Apr. 26, 1949 

